System of space signaling.



1. c. ARMOR. SYSTEM OF SPACE SIGNALING. APPLICATION FILED OCT- 14. I913.

Patented Mar; 13, 1917.

WITNESSES:

1 ran snares manna cannon.

JAMES C. ARMOR, 0F INGRAM. PENNSYLVANIA, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SYSTEM or sraon SIGNALING.

Specification of Letters Patent.

Patented Mar. I3, 191?.

Application filed October 14, 1913. Serial No. 795,033.

To all whom it may concern:

Be it known that I, Janus C. ARMOR, a citizen of the United States, and aresident of Ingram, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Systems of Space Signaling, of which the following is a specification.

My invention relates to systems of space signaling and apparatustherefor, and it has particular reference to the transmitting station of a system of wireless telephony.

One of the objects of my invention is to provide a system of the aboveindicated character which shall be simple in arrangement, effective. efficient and powerful in operation, and shall embody means for effecting variations in the frequency, or the aniplitude. or both. of the electromagnetic waves that are radiated into space from the antenna, in response to acoustic vibrations produced by sound or, in particular, by articulate speech.

Another object of my invention is to embody. in a system such as just referred to, inductive means, the inductance of which may be varied in accordance with sound waves produced by speech.

Another object of my invention is to provide means whereby the inductance of suitable inductive devices may be rendered dependent upon the current of an auxiliary circuit which includes a well-known microphone transmitter, or other suitable device for effecting changes in resistance of an electric circuit in response to vibrations produced by speech.

A still further object of my invention is to provide adequate electrical means whereby the normal inductance of the inductive means referred to, may be maintained at approximately a predetermined value.

A still further object is to provide an in ductive device, which, by reason of its peculiar configuration and arrangement of circuits, is particularly adapted for use in connection with a system of the nature referred to, and which shall be simple, compact and durable in construction, and eflicient and effective in operation. I

In the prior art, it has been customary, in systems of wireless telephony, to. employ a transmitting device directly in the antenna or the oscillation circuit, whereby variations so doing, I employ a in the amplitude or intensity of'the highfrequency oscillations are effected directly by reason of the varying resistance of the transmitter, as will be readily understood.

According to my invention, I propose to vary either the frequency, or the amplitude, or both, of the electrical oscillations and, in magnetizable' core which is associated or linked-with'the highfrequency sending circuit and which is provided with a plurality of windings which are supplied with energy from an auxiliary direct-current source. One of the windings is included in circuit with a reversing switch, an inductance and a variable resistance, whereby the magnetizing current may be adjusted in order to normally maintain the core at any particular flux density or degree of saturation, and the other winding is connected in circuit with a transmitting device, by means of which the current may be varied in response to speech, whereby variations in the inductance of the magnetizable core are effected. In this way, the frequency, or the amplitude, or both, depend' ing upon the location of my inductive device, as hereinafter pointed out, of the elec trical oscillations and,.therefore, of the electromagnetic waves radiated into space, is varied in accordance with well-known principles and the signals transmitted are rendered responsive to the sounds or speech which afi'ect the transmitting device.

It is well known that, if a. current of con stant value be supplied to an oscillation circuit and the frequency thereof be gradually increased, the current in the antenna. circuit increasesto a maximum and then gradually decreases. If these values be plotted, a peaked curve is obtained, the peak occurring when the frequency is that for which the antenna circuit is tuned and the slope thereof depending upon the electrical characteristics of the antenna circuit. Inasmuch as the energy radiated from the antenna is a function of the antenna current, it is evi-.

lation circuit, shall not have exactlythe same natural period, and to work entirely on one side of the peak of the curve heneinbefore mentioned, so that increases-in frequency due to increases in inductance caused by sound waves in the transmitter will cause corresponding increases in the antenna current and, hence, in the intensity or amplitude of the energy radiated, and vice versa. Moreover, I propose to work at substantially the steepest portion of the curve where a very considerable change in the radiated energy may be effected by an extremely slight variation in the frequency, it being understood that the radiated energy varies as the square of the antenna current. 7

It should be understood that, with my inductive de 'ice in the oscillation circuit and a loose coupling between the oscillation circuit and the antenna circuit, the antenna will always oscillate at its own natural frequency, regardless of changes of frequency in the oscillation circuit. Hence, variations in; the intensity of amplitude only of the radiated waves will be effected. If the device is connected in the antenna circuit, however, the frequency also of the waves radiated into space will be changed in response to speech.

In case a close coupling is employed, variations in the frequency of the radiated waves are effected with the inductive device in either the oscillation or the antenna circuit. Perhaps the best arrangement is to employ a loose coupling and connect the inductive device in the antenna circuit, whereby changes of both the amplitude and the frequency of the radiated waves are effected, thereby strengthening or enhancing the effect on the receiving station which, of course, must be sharply and selectively tuned.

In accordance with my invention, m" in ductive device embodies a laminated core of magnetizable material which is provided with a high-voltage, high-frequency winding and preferably with two low-voltage direct current windings.

The high-frequency winding and the direct-current windings are so disposed with respect the one with the other that they are in non-inductive relation. By this term, I mean that the flux produced by the one, does not pass through or link the other, and hence, does not induce a voltage therein in accordance with the well-known transformer action. The inductance of the high frequency circuit may, however, be varied by changes of the direct current, inasmuch as such changes affect the magnetization or saturation of the core.

Reference may be had to my co-pending appiication. Serial No. 711,620, filed July 26, 1912, in which I have disclosed a portion of the subject matter shown and described in this application and set forth in the claims appended hereto. 5

In the accompanying drawing, Figure 1 is a diagrammatic view of a transmitting system embodying my invention, in which my inductive device is connected in the antenna circuit. Fig. 2 iS a similar diagrammatic view showing my inductive device connected as a coupling link between the oscillation and the antenna circuits. Fig. 3 illustrates my: invention, the inductive device being connected as an auto-transformer in the antenna and oscillation circuits. Figs. r, 5, 6, T, S, 9 and 10 being :views showing modified forms of :punchings, or laminations, from which my inductive device may be constructed; together with the circuit connections in certain instances.

Referring to Fig. 1, a generator 1 adapted to generate alternating current from 30,000 to 200,000 oscillations per second. delivers energy to an oscillation circuit 2 which includes an adjustable inductance 3. a condenser 4 and a primary winding 5 of a transforming device 6. A secondary winding 7 of the transforming device 0 is connected in an antenna circuit 8 between an antenna 9 and the ground G and in circuit with an adjustable inductance 10 and my variable inductive device 11.

The generator 1 merely illustrative of any suitable source of high-frequency oscillations, and, by properly arranging the devices and circuit connections of the oscillation circuit, any other suitable source of energy may be employed. such, for instance, as the well-known Poulson are or the rotating spark gap. I urthermore, I do not wish to be restricted to the specifi arrangements, circuit connections and relationship of the source of energy. the osciliation and the antenna circuits. as. broadly considered, I contemplate employing any of the well-known types of circuits employed in this art.

The inductive device 11 comprises a magnetizable core 12 which is preferably composed of a plurality of insulated laminations or punchings (not shown) which are provided with a plurality of openings or'apertures 13 and 11 that are disposed in pairs at right angles, the one to the other. The antenna circuit 8 is threaded through one pair of apertures 13 in a plurality of turns. while two independent windings 15 and 16 are disposed in the other set of apertures 14 and hence, are in non-inductive relation therewith, so that there n be no tendency for high-frequency osciliations to be impressed upon them from the generator 1..

although currents having a frequency double that of the generator 1 may be set up in the windings 15 and 10. the apparatus, however, these currents may be made so small that they will not interfere with the operation of the device.

By proper design of which might otherwise be caused by the variation of current in the transmitter circuit.

Hence, the current, in the winding 16 is maintained substantially constant.

Assuming the circuit connections to be as shown, and the high frequency generator 1, or other suitable source, to be producing electrical oscillations of the desired frequency in the oscillation circuit 2, the operation of the system is as follows:

The reversing switch 19 is first closed upon the proper contact terminals to complete a circuit through the windings 16 of the core 12, after which, the resistance 21 is adjusted until the current which traverses the circuit is the required amount-to saturate the core sufficiently to produce an inductance which shall render the antenna circuit 8 almost in tune or in resonance with the oscillation circuit 2. In some cases the total inductance may be included in my variable inductive device 11, while, in other instances, it may be necessary to employ the auxiliary adjustable inductance 10. In either case, the antenna circuit is tuned to approximately resonant conditions and the inductance thereof maintained substantially constant at a predetermined value, so that the system shall work under the most advantageous and sensitive conditions, whereby effective and reliable operation may be secured.

If the current traversing the windings 15 is varied by means of the transmitter 18 in response to sound or speech, in accordance with well-known practice, it is evident that the degree of saturation or magnetization of the core 12 and, therefore, the inductance of the antenna circuit 8 is varied above and below the predetermined value for which the antenna circuit is tuned. By means of the variable inductance in response to speech, the frequency and amplitude of the electro-magnetic waves radiated from the antenna are accordingly varied.

Referring to Fig. 2, the generator 1 is adapted to deliver alternating current at a frequency of from 1200 to 6000 cycles per second to the primary winding 5 of the transforming device 6, the secondary winding 7 of which is connected across the condenser 4 and in circuit with the adjustable inductance 3 and a spark gap The spark gap 22 may be of any well known type and is adapted to discharge the condenser at periodically, whereby a series of very highfrequency oscillations is produced in the oscillation circuit 2.

The particular means whereby the highfrequency oscillations are produced forms no material part of my invention, except as it performs a useful function in the operation of the system, and any suitable means for producing the same result may be employed.

The inductive device 11 is of the same form as that described in connection with Fig. 1 and is linked through both the oscillation circuit-2 and the antenna circuit 8, and thus serves as a transforming device or coupling between said circuits. The oscillation circuit 2 and the antenna circuit 8 are insulated one from the other and are inductively related, being threaded through the same pair of apertures or openings .13. Direct current windings 15 and 16 are also provided and disposed in the other set of apertures let which are located substantially at right angles to the set just referred to. The connections of the auxiliary windings 15 and 16 with the source of energy are omitted on account of their similarity to the connections already described in detail in connection with Fig. 1. I

The arrangement of circuits just set forthmay be found particularly desirable under certain operating conditions, and, inasmuch as the mode of operation is similar to that already set forth, no further description thereof will be given. l

In Fig. 3, my inductive device 11 is associated with an oscillation circuit 2 of slightly different connections, and the antenna circuit 8, being connected as an auto-transformer which serves as a coupling link between the circuits mentioned. The conductor 23 which constitutes a common circuit for both the oscillation circuit 2 and the antenna circuit 8, is provided with a plurality of-turns or convolutions. which are disposed in one set of openings or apertures 13. Direct-current windings 15 and 16 are also provided and are located in .the remaining set of apertures 14' and are thus non-inductively related to the alternating current circuit 23.

The auxiliary connections of the directcurrent windings 15 and 16 are omitted. However, it will'be, understood that, asthe currents in the direct-current windings are varied, either by adjustment or by small increments in response to speech. variations in the mutual inductance of the oscillation and antenna circuits are effected; whereby changes in frequency and in amplitude of the oscillations in the antenmrcircuit 8 and the waves radiated into space are accomplished.

In r l. u circular punching or lamina tron ll of a modified form from which my inductive device may be constructed, is shown. The uper iures 13 and ll are suostuntiully segmental in shape. and the distunce between the outer edge thereof and the circumference of the punching is large With respect to the distance between the several adjacent. apertures. The nuiin circuit connections are illus cru led diugrzunumth call the antenna circuit 8 being threaded through the pair of apertures 13 while the auxiliary windings 15 and 16 are similarly disposed in the orher set of apertures Punching shown in Fig. is suhstonliully reroinguliir in form Willi rounded (ori with i'wo sets of circulur openings or apertures 13 and ll \v ich are disposed at right angles lio e l I in 53, a punching o soupe is shown l. ring recto lugs 1 and 14: disposed siiuil of Fig. 5.

Reference nui v now he. had to Fig". 7 which illustrates another modified form of punchlamination from which my inducicc inuv be construciml. The punchconstituies an annular uieniher or ch provided, at regular intervals. with openings of cir: form.

-ulur no nuniher and spacing oi' the openings will. of course. depend upon "the condirions of opu'etion. The unteni'u: circuit i illiQHClQil through lhe openings 2% successii'el and in alternate directions, as illuslrsiled in the figure.

In some cases, if may he fouu expedie ir to wind several (onv-iilutions of the antenna circuit through adjacent openings and around the intermediate portion of lhe core. The direct'curreul' windings 15 and iii are wound around the core in u iiluriiliy of convoluiiions in 21 manner similar that PlOfv'Qd in grain-ring ZUmH LlHQS. Clearly the flux produced by the high-frequency or hnteuuo circuit 9 does not link the convolutions of the direel-current windings, inasmuch as they disposed substantially at eight angles rhere'io. Hence. there is no tendenoi to induce oscillaiing currents in these auxiliary windings of ii frequency equal to that of current flowing in the antenna circuit.

In Fig. 8. a punching 29 is of the some general f iii us that illustrated in Fig. Y. except luau. the openings 29* are elongated in a radial :lirec 'ion.

In Fig. u punching her 1 oppositely projecting seciorial end portions, is provided with e. plurality of svn metrically disposed triziuguln r or sectoriul openings 31 having rounded corners. The antenna circuit 8 is Wound in a plurelil v of turns around the central portion of the core. whereas the direct current auxiliary Wind is shown which lugs 15- ;.ind 16 are threaded through the openings 31, in the uninuer hereinbefore described.

ln .lfii 10 u ir icd punching 32", is shown, rhich is pi ieruhlv substantially e liptical in form and is provided with u plurality or sjiui'neiriczillv dispose openings 3% uhirli divide the punching i two outer end uieuil'icrs 35 and a centrally loczzied incinh: The core formed by punchings or lzuuiuutions of this i vpc is similar in lllilll l' re pects lo that of a shell type trunsilioruu-r having El middle and two outer legs. The

antenna circuit 5 is wound around 5 e leg members 35 in the some directioiu u ile the direct current windings l5 and iii are dis posed upon the middle member 36. Willi u core co isiug puuchings of e shape shown i g. 10 l luring w (lisposed toe me see forlh, ihe in pro duced by rhe lii-" 'h-r'equency circ it 8 travei es nifillllll tl outer porlion o. the core with no tendency to pass tliroi i the middle poriion 36 i iereof. The dire flux, however, traverses the mi. i 36 and i'livides to pass through the onier porlions. it is evident. rherefore. the direc: current windings l5 and 16 are non-inductively related to the high-frequency winding 8. although the latter winding may he linked by the flux produced l) "v' the directcurreul; windings:

ilores of zhis. rype are particularly adapted f r ehe reason that ihe alternating-curreui flux traverses the outer portion or" the. core where the radiating surface is comparal'ively large.

hlanifeslily, the various modified forms oi my induciiive device may be connected in the manner shown in Figs. l. 2 and? and are, of course suscepiible of *erietions in form. size and arrangement of parts. Furthermore the specific arrangement and connections shown and descrihed may he varied considerably Without pariing from the spirit and scope of my venlion. and I desire that. only such linu tions shall be imposed as are indicated in the appended claims.

claim as my invennion:

1. The method which 'cousis'ls in producing a magnetizing field by means of a '5', currenli e portionsuch variable electric current, producing a radio frequency alternating current and subject- 111g the radio frequency alternating current to the action of saidmagnetizing field in such a manner as to prevent electromotive forces of a frequency equal to that of the radio frequency current from being induced in the variable current circuit.

2. The method which consists in subjecting a magnetic circuit to the action of a pulsating current, producing a radio frequency alternating current and conducting said radio frequency alternating current within the influence of said magnetic circuit in such a way that variations in the amplitude of the pulsating current will produce corresponding variations in the amplitude of the radio frequency alternating current and in a manner as to prevent electromotive forces of a, frequency equal to that of the radio frequency current from being induced in the pulsating current circuit.

3. The method of amplifying a pulsating unidirectional current which consists in producing a magnetizing field by means of said current, producing a radio frequency alternating current and subjecting said radio frequency alternating current to the action of said magnetizing field in such a manner as to prevent electromotive forces of a frequency equal to that of the radio frequency current from being induced in the pulsating unidirectional current circuit, and that variations in the amplitude of the pulsating current will produce corresponding variations in the amplitude of the radio frequency current.

.4. vThe method of amplifying a variable electric current which consists in subjecting a magnetic circuit to the action of the variable currents producing a radio frequency alternating current, and conducting said radio frequency alternating curren'fl within the influence of said magnetic circuit in such a manner as to prevent electromotive forces from being induced in the circuit of the variable electric current by the radio frequency alternating current, and that the radio frequency current will vary in accordance with variations in the variable current.

5. The method of controlling the flow in an electric circuit of a radio frequency alternating current which consists in producing a magnetizing field by means of a controlling current, and subjecting the radio frequency current to the action of said magnetizing field in such a manner as to prevent electromotive forces of a. frequency equal to that of the radio-frequency current from being induced in the controlling current circuit, and that the amplitude of the radio frequency current will depend upon the amplitude of the controlling current 6. An apparatus of the class described,

comprising a magnetic core, a high frequency winding associated therewith, a second winding associated with said core and in non-inductive relation to said first winding, means associated with said second winding for producing a predetermined magnetic flux in said core, and means responsive to external conditions for varying the flux in said core.

7 In a system of Wireless signaling, the combination of an antenna circuit supplied by a source of high frequency energy, a magnetizable member having a winding thereon included in said antenna circuit, a second winding on said member in noninductive relation to the first winding and means for varying the current supplied to the second winding.

8. Means for amplifying a variable electric current comprising means for producing a magnetizing field by the variable current, a circuit supplied by a source of radio frequency alternating current, and means for subjecting said radio frequency alternating current to the action of said magnetizing field in such a manner as to prevent electromotive forces of a frequency equal to that of the radio frequency current from being induced in the variable currentcircuit and that. the amplitude of theradio frequency current will vary in accordance with variations in the amplitude of the variable current.

9. The combination with an electric circuit supplied by a source of radio-frequency alternating current, of means for controlling the flow of current in the circuit comprising a magnetizable member having a winding including in said radio frequency circuit, two other windings on said member in noninductive relation to the first winding, means for supplying one of said last named windings with a constant-direct current, and means for supplying the second of said last named windings with a variable current.

10. The combination with a high frequency winding, of an inductive device associated therewith, means disposed in non-inductive relation to said winding and embodying a sourceof energy for maintaining a predetermined inductance of said device, andmeans associated with said device and said source of energyand responsive to external conditions for effecting changes in the inductance of .said device.

11. In a wireless system, the combination with an inductive device, an oscillation circuit, an antenna circuit and an auxiliary circuit, all linking-said device, the auxrliary circuit being non-inductively related to the other circuits, of means responsive to varying external conditions for changing the 1nductance of said device.

12. In a system of wireless signaling, the combination with an oscillation circuit and an antenna circuit normally maintained slightly out of tune, of an inductive device associated therewith, and means associated with said device and in.non-inductiverelation to said oscillation circuit and said an tcnna circuit for: effecting variations in the relative tuning of said circuits in response ts predetermined external conditions.

13. In a system of wireless signaling, the combination with a high-frequency oscillation circuit and an antenna circuit in electro-responsive relation therewith, of a magnetizable member having a plurality of windings in non-inductive relationship with each other, a source of direct'current and a transmitter connectedlin series relation with one of said windings, a second of said windings being included in one of said first 7 namedcircuits.

14. In a system of wireless signaling, the combination with a sourceof alternatingcurrent energy, an oscillation circuit and an antenna circuit in electro-responsive relation therewith, of a magnetizable member has?- ing a winding associated with one of said circuits, a plurality of direct-current windings in non;inducti;-Je relation thereto and severally connected to a direct current sourceof energy, and means included in circuit with one of said direct-current windings "for varying the current traversing said winding in response to speech.

15. ln-a system er wireless signaling, the combination with a source of alternating current energy, an oscillation circuit and an antenna circuit in electro-responsive relation. therewith, of amagnetizable member having a inding associated withljone of said circuits, a Qluralit'y of direct current windings. in non-inductive relation theret and severally connected to a direct-current source of energy, means included in circuit with one of said direct-current windings for regu iating the current therein, and separate means in the other of said direct-current windings for efiectifng current variations therein responsive to sound waves.

16. in a system of wireless telephony, tlrfe combination with a source of high-frequency energy, an oscillation circuitgand an antenna circuit, of an inductive device havinga pluality of inductively related windings connected respectively to said oscillation circuit and said antenna circuit, and a direct-current winding disposed in non-inductive relation to said first windings for varying the inductance of said device.

17. In a system of wireless telephony, the combination with asource of high-frequency energy, an oscillation circuit and an antenna circuit, of an inductive device having a plurality of inductively related windings connected respectively to said oscillation circuit and said antenna circuit, an auxiliary winding in non-inductive relation to said first windings, a source of direct current, and a transmitter connected circuit with said last winding.

18. In system of wireless signaling, the combination with a magnetizable core, a high-frequency oscillation circuit and an antenna circuit associated with said core and mutually related; of a 'direct-current auxiliary winding disposed at substantially 'ht anglies thereto and in non inductive rea non therewith.

In testimony whereof, I have hereunto subscribed my name this 11th day of {Ectoiie'r 1913. 5

JAMES C. ARMQR.

' Witnesses:

GEO. M. DURANT, CLARENCE P. Nines. 

